JPH07264570A - Multi-point communication system - Google Patents

Abstract

PURPOSE:To easily apply this multi-point communication system to various formats of multi-medium communication having sufficiently high quality among many points. CONSTITUTION:Voice/video signals from visual telephone sets 121 to 12n are decoded by decoders 171 to 17n and applied to a mixer/synthesizer 183. The mixer/synthesizer 183 synthesizes respective voice/video signals and converts the synthesized signal into a synthetic signal to be arranged in a multi-window. The synthetic signal is converted into a signal for a broadcasting channel through a program receiving interface 164b, an encoder 15m and a channel processor 163 and applied to TV receivers 111 to 11n in respective subscriber's homes as a broadcasting channel signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multipoint communication system.

[0002]

2. Description of the Related Art In recent years, many systems for performing moving image communication have been put into practical use due to improvements in image processing technology and network technology. One of them is a video conference system, which ranges from a floor-mounted type with a dedicated cabinet to a desktop type using a personal computer or workstation as a communication terminal.
In addition, not only connecting two points, but also connecting three or more points have been developed.

For example, in a video conference system, the face image of each participant is basically transmitted and the conference is proceeded while watching the state of the other party. And especially in a multipoint video conference system, the face images of a plurality of partners are displayed at the same time,
The conference is held while watching all participants.

For example, in the literature: IEICE Technical Research Report, 1990, IE90-49, "Multipoint multimedia communication conference system PMTC for B-ISDN", there are two types of multipointer conference systems for communication. The realization method is shown.

One of them is a star type connection as shown in FIG. 2 (a), and the other is a mesh type connection as shown in FIG. 2 (b). When realized by this star-shaped connection form, the terminal of each participant is connected to the multipoint communication connection device via the network. Since the multipoint communication connection device has a function of switching or synthesizing a plurality of voices and images, each participant can receive the voices and images of a plurality of parties by communicating with the multipoint communication connection device. You can do it.

Further, in the case of being realized by the mesh type connection form, a logical communication channel is set for each participant and a plurality of decoders are used to receive voices and images of a plurality of partners.

[0007]

However, in the case of the connection configuration shown in FIG. 2A, it is not easy to require the multipoint communication connection device. Furthermore, it is common to switch and display from multiple partner images, but when transmitting and displaying multiple partner images combined by multi-window, sufficient quality can be obtained in terms of transmission capacity. There was also the problem of not having it.

Further, in the case of the connection configuration shown in FIG. 2B, basically, in order to display a plurality of images,
It is necessary to set a logical communication channel between each participant and to use a plurality of decoders, which causes a problem of increasing the scale of hardware.

Due to the above problems, it has not been possible to realize a system that can easily hold a communication conference between multiple points with sufficient quality. Furthermore, there has been a demand for providing a mechanism applicable to communication between various types of multipoints other than communication conferences.

[0010]

The multipoint communication system of the present invention has the following configuration in order to solve the above problems.

(1) That is, the multi-point communication system includes an audio signal, a video signal, a character signal,
Or, a broadcast signal output means for outputting any one of these signals or a combination of these signals to a transmission path through a broadcast channel and supplying the signal to a broadcast receiving device at each subscriber's house. Then, further, an audio signal, a video signal, a character signal from the communication device of each subscriber's house,
When either a control signal (for example, communication mode information or the like) or a combination of these signals is given through a communication channel of a transmission line, a combining means for combining these signals into a required form and outputting a combined signal. Equipped with. Furthermore, the broadcast receiving device is provided with broadcast signal converting means for converting the composite signal into a signal of a broadcast channel and giving it to the broadcast signal output means for outputting to a broadcast transmission path on the broadcast channel.
The above problem is solved by outputting the received signal acoustically, visually displaying the content of the received signal, or a combination thereof.

The broadcast receiving device is, for example, a TV.
An image receiver, a workstation, an audio receiver, etc. are assumed. As the communication device, for example, a telephone device with a video camera, a workstation, a FAX device, etc. are assumed. A video reproduction device, an audio output device, or the like can be connected to this communication device to give a video signal or an audio signal. Further, the control signal is communication mode information or the like, and for example, a signal indicating whether the communication is only voice, or voice + video communication is assumed.

(1a) Incidentally, as the above-mentioned transmission line, for example, a wired transmission line, a wireless transmission line, an acoustic transmission line, or the like is preferable. Further, it is preferable to use a CATV line, a public telephone line, an optical fiber line, an ISDN line or the like as the wired transmission line.

(1b) Further, as the synthesizing means, it is preferable to synthesize a signal provided from each subscriber's house into a signal for multi-window arrangement and then provide it to the broadcast signal converting means. Further, it is also preferable to reproduce a recorded signal recorded in advance (for example, from a VTR) and synthesize the reproduced signal so as to be arranged in the multi-window.

(1c) Further, the broadcast signal output means, the synthesizing means, and the broadcast signal converting means are configured in a center station. Further, the center station is provided with a transmitting means for generating a call signal for each subscriber's home and giving it to the broadcast receiving device or the communication device of each subscriber's home through the broadcast channel or the communication channel, so that the subscriber can be called. .

The synthesizing means further has, for example, a function of counting the number of participants who participate in a conference and the like, and a function of synthesizing a plurality of videos by a multi-window, so as to correspond to the number of participants. It is also possible to compose a plurality of images by setting the window layout. In addition, by having a function of counting the number of participants and a function of identifying the video format transmitted by the participants, by setting the multi-window arrangement corresponding to the number of participants and the video format transmitted by the participants, It can also be configured to combine a plurality of images.

[0017]

According to the multipoint communication system of the present invention, an audio signal (for example, own voice), a video signal (for example, own face image), a character signal (for example, message), a control signal (from a subscriber's house) For example, receiving the communication mode information) and the like, a synthesis signal (for example, a multi-window image and its audio signal) is obtained from these signals by the synthesis means. Then, the combined signal is converted into a broadcast channel signal by the broadcast signal converting means, output to the transmission path, and transmitted to each subscriber's house. , The content of the composite signal is given.

As a result, the broadcast receiving device acoustically outputs the received signal (for example, outputs the voice from each subscriber).
Alternatively, by decoding the content of the received signal, the content can be output as a video (image output in a multi-window).

With such a structure, each subscriber receives and views and listens to voices and images from other multipoint subscribers, and further sends his or her own voice or face image through the communication device. Can communicate.

From the subscriber's house, not only the face image,
Any video can be sent out by a video camera or the like. It is also possible to send out messages and graphs as text files and still images. Also, a subscriber can communicate with other subscribers by sending out sound or only sound without sending out video. Then, since a signal is given to each subscriber's home through the broadcast channel, it can be given in a broadcast manner.

By configuring each of the above means in the center station, it is possible to configure each subscriber's home without taking a special connection form as in the prior art.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention applied to a multipoint communication system will be described with reference to the drawings.

[First Embodiment]: FIG. 1 is a block diagram of a multipoint communication system of the first embodiment. In FIG. 1, the multipoint communication (MPC) system is mainly composed of a center facility 140,
Optical fiber network 130 and subscriber homes 101 to 1
It is composed of 0n.

The MPC system of the first embodiment is a CA
It is realized by fusing a broadcasting service of TV (cable television) and a communication service of N (narrow band) -ISDN.

Therefore, the subscriber homes 101 to 10n are
TV receivers 111 to 11n and TV phones 121 to 12
n. The center facility 140 mainly includes a CATV headend unit 141, a communication / broadcast interface unit 142, and a program providing unit 14. Then, the optical fiber network 130 is C
There are a broadcast channel for ATV and a communication channel, and interfaces from this network to the subscriber homes 101 to 10n are performed by the interface units N1 to Nn. Further, the interface from the optical fiber network 130 to the center equipment 140 is the interface unit M.
1 and M2.

The CATV headend unit 141 of the center facility 140 is provided with the m coding device 1 for program broadcasting.
51 to 15 m and a program receiving interface section 164
, Channel processor 163, and video recording medium 16
1 and a video server 162.

Then, the communication / broadcast interface section 142 of the center equipment 140 has TV telephone receiving decoders 171 to 17n for N-ISDN, a recording / reproducing file 181, a voice / video / document file, a server 182, and a voice. A video mixing / synthesizing device 183.

Then, the program providing unit 143 provides the program receiving interface unit 164 with audio / video signals from the TV rebroadcast facility, the independently produced program, the program providing company, and the like. The program receiving interface unit 16
4a is a coding device 151 to 1 for broadcasting audio / video signals.
Give to 5m. Also, a mixing / synthesizing device 1 for audio / video
When a mixed / combined signal of audio and video from a plurality of subscribers from 83 is given to the program receiving interface section 164b, it is given to the coding device 15m.

Then, the coding devices 151 to 15m perform coding or modulation on the audio / video signals so as to make them signals for transmission, and give the coded signals to the channel processor 163. Further, the video signal recorded on the video recording medium 161 is also given to the channel processor unit 163 as necessary. And the channel processor 1
Reference numeral 63 outputs a coded signal, a video signal, etc. through a broadcast channel through an interface unit M1 to the optical fiber network 130. The signal of this broadcast channel is given to each subscriber home 101 to 10n.

The CAT of the subscriber's home 101 to 10n
The V receivers 111 to 11n receive signals from the broadcast channel from the interface units N1 to Nn, select a required broadcast channel signal, and receive and output video and audio.
This video and audio includes the program reception interface unit 16
Since the signal from 4b is also included, audio / video from each subscriber can be given from this signal.

Therefore, a mechanism for giving audio / video from each subscriber to the CATV broadcast channel will be described next.

Each subscriber has his or her own TV telephone set 121 to 12
n using n to transmit its own audio and video using the communication channel of the TV telephone receiving decoders 171 to 171 of the center equipment 140.
Give to 17n. Then, the TV phone reception decoder 17
1 to 17n decode videophone audio and video, and provide the decoded signals to the audio / video mixing / synthesizing device 183.
Here, processing is performed for mixing the audio from the decoded signals from the subscribers, synthesizing the images, and arranging them in the multi-window. Furthermore, the audio / video mixing / synthesizing device 183 also takes in shared material signals and presentation signals from the audio / video / document recording / playback file 181.
It is processed and mixed / combined with the signal from the subscriber.

The signal thus obtained by being processed by the audio / video mixing / synthesizing device 183 is given to the program receiving interface section 164b. And
The program receiving interface unit 164b gives signals such as audio / video / documents from the audio / video mixing / synthesizing device 183 to the encoding device 15m in order to put them on the broadcast channel (for example, channel M), and encodes them. Let them do it. Then, the encoded signal is given to the channel processor 163, converted into an optical signal of the channel M of the broadcast channel, output to the optical fiber network 130, and supplied to each of the subscriber homes 101 to 10n.

By this supply, the subscriber homes 101 to 1
The 0n CATV receivers 111 to 11n select and receive the broadcast channel M, so that the CATV receivers 111 to 111n.
In 11n, the intention can be received from each subscriber by receiving the voice and video of the call made to the center equipment 140 through the communication channel by the TV phones 121 to 12n. Furthermore, the reply is sent to the TV phones 121 to 12n.
You can also do it in.

With the above-mentioned mechanism, it is possible to perform multipoint voice and video communication. In addition, the existing material video and audio of the center equipment 140 are recorded / reproduced by the audio / video / document file 181.
By using the video server 162 and the video server 162, existing material images and audios can be streamed through the broadcasting channel to be used as a reference for multipoint communication.

(Structure of the video synthesizing unit of the audio / video mixing / synthesizing device 183): FIG.
9 is a functional block diagram of a video composition unit in the composition device 183. FIG. In FIG. 4, the image synthesizing unit mainly includes a scaler 32.
1-32n, the display output memory 320, and the control circuit 33.
0 and an output unit 340.

Decoded video data from the TV phone reception decoders 171 to 17n are input to the video input terminals 301 to 30n. The decoded video data is provided to the skaters 321 to 32n, respectively. The scalers 321 to 32n are composed of a spatial filter processing circuit, a buffer memory, and the like, and the decoded video data is converted into a video of a size designated by the control circuit 330 and written in the internal buffer memory.

The control input terminals 311 to 31n are connected to
When the communication information, that is, "audio only", "audio + CIF video", or "audio + QCIF video" is given from the TV phone receiving decoders 171 to 17n, the control circuit 330 causes the number of windows to be combined and decoding. The optimum window size and window layout are determined from the information on the number of pixels of the video. This CIF (Common
Intermediate Format: Common intermediate format, 352 pixels x 288 lines), QCIF
(Quarter CIF, 1/4 CIF: 176 pixels x
144 line) is CCITT Recommendation H.264. 320 is a standard video format in a terminal device to which it is applied.

Further, the control circuit 330 writes the plurality of video data converted into the designated window size into the memory space corresponding to the designated arrangement in the display output memory 320 so that each of the buffer memories of the scalers 321 to 32n can store the image data. It controls reading and writing of the display output memory 320. Then, the display output memory 320 reads the video data read as the combined video by the output unit 340 and outputs the video data to the video output terminal 341. This output video data is supplied to the program receiving interface section 164b.

(Effects of First Embodiment): According to the multipoint communication system of the first embodiment described above, the video of all the participants is included in the video broadcast by the broadcast channel of CATV, and all the participation. Since participants can also listen to the voice of the person,
You can realize the same service as gathering and interacting in one place. Moreover, since the audio / video broadcast on the CATV broadcast channel is generally higher than the quality of the TV phone, it is easier to obtain the high-quality video and audio than the conventional TV phone system having the multipoint communication function. The system can be realized.

Further, since the broadcast channels of mixed / synthesized audio / video / documents can be received by an unspecified person, it is possible to participate as an observer in the discussion or the like, or to view and discuss the channels. If you want to join
It is also possible to newly add by making a call to the communication / broadcast interface unit 142. Therefore, services that are very suitable for open discussions and well-end meetings can be realized.

By preparing presentation materials and the like in the audio / video / document recording / playback file 181, it is possible to carry out an efficient discussion.

[Modification of First Embodiment] In the configuration of the first embodiment described above, in a conference by multipoint communication, it may be desired to keep the conference private to subscribers other than the specific subscriber. In response to such a request, for example, a signal such as an audio / video / document transmitted on a broadcast channel is scrambled and transmitted to the subscriber's home. Then, the subscriber who participates in the conference is given a key (decoding code) for descrambling, and by applying this key to his TV receiver, the scrambled image is restored to a live image and received. As a result, it is possible to easily implement a conference privately to a subscriber who does not have a key.

[Second Embodiment]: FIG. 2 is a block diagram of a multipoint communication system of the second embodiment. In FIG. 2, the same parts as those of the first embodiment are designated by the same reference numerals, and the characteristic difference is that between the TV telephones 121 to 12n of the subscriber homes 101 to 10n and the center equipment 140. The ISDN public network 230 is used to use this line as a communication channel. Therefore, the ISDN public network 230 and the subscriber homes 101 to 10n
And interface units B1 to Bn. Further, the ISDN public network 230 and the center equipment 140 are interfaced with interface units D1 to D3.

As in the case of the first embodiment, the broadcasting channel of CATV is used as the broadcasting channel to supply the signal from the center facility 140 to each of the subscriber homes 101 to 10n. The configuration in which the multi-point communication system is applied to, for example, a "Cram School" system with such a configuration will be described below. Since the facial expressions of other participants can be understood compared to the “Cram School” in the form of communication, it is possible to realize a service similar to that when gathering in a classroom. Then, the teacher of the cram school prepares necessary materials and the like in the file 181 for recording / reproducing audio / video / documents in advance so that they can be controlled by using the low speed data of the TV phone. Teachers can also teach effectively from a subscriber's home with the same equipment as other students.

Here, FIG. 5 shows an example of a multi-window layout diagram of the images projected on the image receivers 111 to 11n in the case of the "Juku" system. In FIG. 5, area 400 is the entire composite video, and window 401
Is a video window for presentation, window 402 is a video window for a teacher, window 403 is a window for speakers and interrogators, and windows 404 to 407 are windows for students. Such a window arrangement is mainly realized by the processing of the video synthesizing unit of the audio / video mixing / synthesizing device 183.

(Effects of the Second Embodiment): According to the multipoint communication system of the second embodiment, the CATV and ISDN are the same as in the first embodiment.
It is possible to realize a system in which all participants can see and hear the facial expressions of all by using the public network. Moreover, since CATV is used, it is possible to transmit video signals and audio signals with high quality.

Moreover, when applied to the "Cram School" system, the lesson can be conducted as if in the same classroom. In addition, since it can be used by simply receiving the broadcast channel, it can also be used for observation for class visits and teacher training. Furthermore, as a communication channel, I
By using the SDN public network 230, the ISDN line currently in operation can be effectively used, and the reliability of communication can be secured.

Further, unlike the audiovisual participation program in the two-way CATV, the communication / broadcast interface 164 automatically mixes / synthesizes the audio / video, so that the CATV
If a lease channel (a channel that can be lent to subscribers) or the like is secured in advance as a channel, multipoint communication can be realized without making a special operation effort.

"Variation of Second Embodiment": When the "Juku" system of the multipoint communication system of the second embodiment is used in, for example, a computer shopping system, the trader uses a window for presentation. While explaining the product etc., multiple people in distant places look at each other's facial expressions,
It is also possible to realize a new service that allows you to make purchase decisions while consulting.

Then, an example in which each subscriber makes a call to the communication / broadcast interface section 142 has been described.
Due to the nature of the usage pattern, when communication is started by making a TV phone call from the operating company side to the subscriber side, a TV phone is provided in the communication / broadcast interface section of the operating company side, and the user subscribes using the communication channel. It can be realized by making a call to the TV phone in the house.

In the case of a distributed multipoint conference, it is preferable to scramble the CATV broadcast channel for broadcasting depending on the nature of the conference. In this case, for example,
The subscriber who participates in the conference is given a key (decoding code) for descrambling, and by applying this key to his TV receiver, the scrambled image is restored to a live image and received. , It is also possible to easily implement a conference privately for subscribers who do not have a key.

(Other Embodiments): (1) In the above embodiments, the signal of the broadcast channel was transmitted by CATV, but the present invention is not limited to this. It can also be realized by a transmission line or the like. In addition, it can be applied to public telephone lines, optical fiber lines, ISDN lines, and the like.

(2) Further, the communication channels of the above-mentioned embodiment are the optical fiber network 130 and the ISDN public network 23.
In addition to using 0, a CATV line, a public telephone line, a wireless line, or an acoustic transmission line can be used.

(3) Further, the TV receivers 111 to 11n
May be a workstation, an acoustic receiving device, or the like. Furthermore, the video telephone devices 121 to 12n
May be, for example, a workstation, a FAX machine, or another communication apparatus. Further, the communication device may be configured so that a video signal from a video reproducing device is given and transmitted, or an audio signal from an audio output device is transmitted.

(4) Furthermore, in the above embodiment,
In addition to the transmission of audio and video, it is also preferable that the character information is transmitted through a broadcast channel.

[0057]

As described above, according to the multipoint communication system of the present invention, an audio signal, a video signal, a character signal, etc. are output to a transmission path through a broadcast channel and given to a broadcast receiving device at each subscriber's house. When an audio signal, a video signal, a character signal, a control signal, etc. from the broadcasting signal output means and the communication device of each subscriber's house are given through the communication channel of the transmission line, they are combined into a required form and combined. The broadcast receiving device is provided with a synthesizing unit for outputting a signal, and a broadcast signal converting unit for converting the synthesized signal into a signal of a broadcast channel and giving it to the broadcast signal output unit for output to a broadcast transmission line on the broadcast channel. By outputting the signal acoustically and visually observing the content of the received signal, it is easy to realize multi-point communication in various forms with sufficient quality. It can be.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a multipoint communication system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional multipoint communication connection configuration.

FIG. 3 is a configuration diagram of a multipoint communication system of a second embodiment.

FIG. 4 is a functional configuration diagram of a video synthesizing unit in the mixing / synthesizing device according to the embodiment.

FIG. 5 is a multi-window layout diagram of a composite video image according to an embodiment.

[Explanation of symbols]

101-10n ... Subscriber's house, 111-11n ... TV receiver, 121-12n ... TV telephone, 130 ... Optical fiber network, 140 ... Center equipment, 141 ... CATV
Headend 142, communication / broadcast interface section,
143 ... Program providing unit, 151-15m ... Encoding device, 1
61 ... Video recording medium 162 ... Video server 163
... Channel processor, 164 ... Program receiving interface section, 171 to 17n ... TV telephone receiving decoder, 1
81 ... Recording / playback file, 182 ... Server, 183 ...
Audio / video mixing / synthesizing device, 230 ... ISDN public network.

Claims (7)

[Claims] 1. Broadcast signal output means for outputting any one of an audio signal, a video signal, a character signal, or a combination of these signals to a transmission path through a broadcast channel and giving the broadcast signal to a broadcast receiving device at each subscriber's house. When an audio signal, a video signal, a character signal, a control signal, or a combination of these signals from the communication device of each subscriber's house is given through the communication channel of the transmission path,
A synthesizing means for synthesizing these signals into a required form and outputting a synthesized signal, and a broadcast for converting the synthesized signal into a signal of a broadcast channel and giving it to the broadcast signal output means to output it to a broadcast transmission line on the broadcast channel. A multi-point communication system, characterized in that the broadcast receiving device outputs the received signal acoustically, the content of the received signal visually, or a combination thereof. . 2. The multipoint communication system according to claim 1, wherein a signal is transmitted using any of a wire transmission line, a wireless transmission line, or an acoustic transmission line as the transmission line. Multipoint communication system 3. The multipoint communication system according to claim 2, wherein the cable transmission line is a CATV line, a public telephone line, an optical fiber line, or an ISD.
A multipoint communication system characterized by using one of N lines. 4. The multipoint communication system according to any one of claims 1 to 3, wherein the synthesizing means synthesizes a signal provided from each subscriber's house into a signal for multi-window arrangement and broadcasts the signal. A multipoint communication system characterized by being applied to signal conversion means. 5. The multipoint communication system according to claim 4, wherein the synthesizing means reproduces a recording signal recorded in advance and synthesizes the reproduced signal so as to be arranged in a multiwindow. And the multi-point communication system. 6. The multipoint communication system according to claim 1, wherein a center station is provided with the broadcast signal output means, the synthesizing means, and the broadcast signal converting means. A characteristic multipoint communication system. 7. The multipoint communication system according to claim 6, wherein the center station generates a call signal for each subscriber's home, and a broadcast receiving device or communication for each subscriber's home is made on the broadcast channel or communication channel. A multipoint communication system characterized by comprising a transmission means for giving to a device.